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不同层错能铜合金表面纳米化研究

时间:2018-07-19 21:15来源:毕业论文
摘要表面纳米化技术,是近二十年来发展极快的一项极具潜能的纳米技术。本文以T2纯铜以及H70铜锌合金为实验原料,利用新研制的旋转加速喷丸设备(RASP)进行处理,以实现纯铜以及

摘要表面纳米化技术,是近二十年来发展极快的一项极具潜能的纳米技术。本文以T2纯铜以及H70铜锌合金为实验原料,利用新研制的旋转加速喷丸设备(RASP)进行处理,以实现纯铜以及铜合金的表面纳米化,通过对比这两种层错能不同的铜合金,进行铜合金的表面纳米化研究。实验参数:钢珠直径3mm,线速率25m/s,每次喷丸重量12.5kg,每面4次。25893
RASP处理得到的两个表面纳米化铜合金样品,除了对其金相和硬度进行了观察和测试,还使用了Auriga FIB聚焦离子束显微镜与透射电子显微镜(TEM)等对其相关性能进行了测试与表征,并进行了拉伸测试。最终,得到如下的结论:
1.铜合金经过表面处理,表面发生强烈塑性变形,晶粒细化,晶粒尺寸由表面至芯部逐渐变大,呈梯度分布。
2.经过表面纳米加工过后的铜锌合金,其表面层硬度由表面至芯部逐渐减小,且最表层的硬度值最大;
3.经过表面纳米加工后的铜锌合金,其硬度比表面纳米加工后的纯铜硬度有明显提高。
4.通过拉伸试验可知,处理后试样的屈服强度均提高,且铜锌合金为纯铜试样的两倍,抗拉强度也提高,但平均塑性变形率下降。
关键词  表面纳米化  旋转加速喷丸  铜锌合金  层错能  硬度  塑性变形
毕业论文设计说明书外文摘要
Title   A research on copper alloy of different stacking fault energy by surface nanocrystallization treatment
Abstract
Surface nanocrystallization is a promising nanotechnology that developed rapidly in nearly two decades. In the paper, T2 pure copper and H70 copper-zinc alloy were treated by a new Rotational-Accelerated-Shot-Peening (RASP) equipment in order to achieve surface nanocrystallization. By comparing the two copper materials of different stacking fault energy, surface nanocrystallization of copper alloy can be better studied. Experimental parameter includes: the projectile diameter is 3mm, rate is 25m/s, 12.5kg of the projectile each time and every side was treated for 4 times.

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The surface nanocrystallization samples induced by RASP were tested and characterized by Auriga FIB Microscope, besides to observe microstructure and testing hardness. Following is the results:
1.Metallographic structure on surface nanocrystallization layer of copper alloy treated by RASP has a gradient distribution along the thickness direction. With increasing depth from the RASP treated surface, grain sizes increase and vary from nanometer level to micron level, the top surface layer is fine;
2.The hardness on surface nanocrystallization layer of copper alloy gradually decreases along the thickness direction, the top surface layer is maximum;
3.The hardness of H70 treated by RASP is higher than that of the pure samples.
4.According to tensile test, the yield strengths of two samples treated by RASP have both been increased, and the yield strength of H70 sample is twice than that of the pure one. In addition, the strength of extension has also been increased. But theirs average ductility were decreased.
Keywords  Surface nanocrystallization;  RASP;  Copper-Zinc alloy;  Stacking fault energy;  Hardness;  Plastic deformation
目   次
1 绪论    1
1.1 表面纳米化的制备方法    1
1.2 表面自身纳米化的结构特征和性能    3
1.3 塑性变形导致纳米化机理    4
1.4 铜锌合金的介绍    5
1.5 表面纳米化材料的应用    5
1.6 层错能    6
1.7 本文研究的内容    6
2 实验部分    8
2.1 实验材料与设备    8
2.2 试样的制备与测试    9 不同层错能铜合金表面纳米化研究:http://www.lwfree.cn/cailiao/20180719/19879.html
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